The 29W USB-C power adapter with fast charging on the iPad Pro isn’t only capable of quickly charging an iPad Pro while its screen is turned off – most notably, it can both sustain and power the device considerably while it’s working hard used at full brightness. The 29W adapter is remarkably consistent in battery gains in a variety of conditions and it dramatically reduces the amount of time required to charge the iPad Pro.
I could guess Apple’s motivations for selling the 29W power adapter as a separate accessory (one could argue that fast charging for the iPad Pro wasn’t ready to ship last year). In an ideal world, however, the 29W adapter and USB-C to Lightning cable should be included in the 12.9-inch iPad Pro box.
The difference is insanely huge! I expected a difference, but not this.
Make sure to check out Federico’s charts.